Liquid-fuel-burning apparatus



BESTAVAILABLE Nov. 2 1926. 1 1,605,423

A. H. BALLARD LIQUID FUEL BURNING APPARATUS- Filed Jan. 19. 1925 2 Sheets-Sheet 1 v luv/021 707? flrZizzerliBazla rd 2 Sheets-Sheet 2 3ESTAVAILABLE com Nov. 2 1926.

' A. H. BALLA'RD LIQUID- FUEL surname APPARATUS Filed Jan. 19. 1925 Patented Nov. 2, 1926.

UNITED STATES PATENT OFFICE.

ARTHUR H. B ALLA RD, BOSTON, MASSACHUSETTS, ASSIGNOR TO BALLARD OIL BURNING EQUIPMENT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS Application filed January This invention relates to liquid fuel burning apparatus and particularly to apparatus employing a nozzle having an orifice through which the fuel is discharged. The

object of the invention is to provide means for maintaining the orifice open and pre-' venting. accumulations of carbon or other material which tend to obstruct the flow of the fuel and interfere withthe proper func-..

tioning of the apparatus.

While the invention may have other use ful application, it is of particular vvalue in connection with oil burners where the oil is forced under pressure through a relative- 1y small orifice ,into the combustion chamber, air being supplied exteriorly of the nozzle to commgle with the discharged 011. Under such conditions the. intense heat to which the nozzleorifice is expose tends to produce a carbonization which gradually buildsup. an encrustation cutting off or so reducing the supply of fuel that the flame may be extinguished or the normal function of the burner otherwise interfered with.

The invention .will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while the scope will be'more, particularly pointed out in the appended clalms.

1n the drawings,-

Fig. 1 illustrates diagrammatically the general arrangement of a liquid fuel burning apparatus embodying one form of the invention;. v

Fig. 2 is a detail in elevation and partial cross section on an enlarged scale showing the burner nozzle and automatically actuated cut-out switch for the oil feeding motor;

Fig. 3 is a diagrammatic detail showing the cut-out switch in its open position; and

Fig. 4 is a sectional detail in elevation showing the admission orifice and its valve when the clearing device is retracted in the normal operation of the burner.

Referring to the drawings and to the illustrative embodiment of the invention therein shown, the apparatus is shown applied to a suitable combustion chamber, herein embodied in the boiler 5, to which chamber oil or other liquid fuel is supplied through the nozzle 7 the fuel when discharged from the orifice of the nozzle be- 19, 4925. Serial No. 3,222.

ing comingled with air delivered about the nozzle through the surrounding air-supply chamber 9 and regulated by the damper 11 or other suitable regulator.

To supply the fuel under the necessary pressure, there; is provided the fuel pump 13 driven by thevelectric motor 15, the pump drawing its supply through the supply pipe 17 and delivering it to the nozzle through the delivery pipe 19. The fuel is withdrawn by the pump through the pipe 17 from the supply tank 21 provided with the vent pipe. 23, there being also provided the bypass 25 above the pump and pressure regulating valve 27 such that a uniform predetermined pressure may be maintained at the nozzle.

The feed motor 15 is supplied with current from any suitable source through the control switch represented at 29. The mo-' for circuit indicated at 31 may include a switch controlledby the room-thermostat 33 for opening the circuit on an excessive rise of temperature of the space to be heated and closingit on the lowering of such temperature, a similarly thermostatically colitrolled switch 35-responsive to the tempera-- ture in the stack or flue 37 leading from the combustion chamber, and the pressure responsive switch 39 for opening the circuit on excessive rise of boiler pressure and conversely closing the circuit on a drop in pressure. Additionally,there is also provided a switch 41 cooperatively related to the nozzle, the construction and function of which is hereinafter described.

Referring to the nozzle and the switch 41 (Figs. 2 and 3), the former is provided with a clearing device arranged to clear accumulated obstructions from the small oil discharge orifice 43, such clearing member comprising the reciprocatory plunger 45 having the small reduced end 47 of a size adapted to enter and clear the orifice of any accumulations. In the normal or inactive condition of the burner the plunger is in its forward position with its reduced end entering and protruding through the orifice 43. The reduced end of the plunger passes through a central perforation in the guide plate 49, the latter being suitably perforated to permit the free passage of oil therethrough, While the rear end of the plunger enters an enlarged chamber 51 and is connected to a stud 53 secured to the diaphragm 55 attached to the corrugated or bellows-like metallic wall 57, the forward end of which is fianged'and held between co-acting walls of the chamber 51.

The oil under pressure is supplied to the oil supply chamber 09 which opens into the chamber 51 through a passage 61. The lat ter is tapered or flared toward the interior and provided with a conical valve 62 which is so held (see Fig. 4) during the normal operation of the burneras to provide a suppl'y'orifi'ce of" restricted cross sectional area an'd'of such'relation to the size of'the orifice 43 so that in the operation of the burner, with the orifice 43"unohstructed and the oil'flowiiig freely therethrough, the normal working presstire of the ,oil' within the chamberf'51' is'less than'the supply pressure within the supply chamber 59. The valve 62 has a stem 63 'mo'unted' to slide vertical ly inthe'guide black 64}, the top of the stem engaging with acam plate 65 carried by thei plunger 45'. v

When the burner is inactive the corrundiwnrm is contracted and the clearing rod movesto'its forward or protruding position uiider the constantly acting pressure 0f"t he spring 66 located between the head of the stud 53 and the threaded pin 67. In

this position it brings the low part of the gain" plate 65; against the valve stem 63 which latter 'is lifte'dby the spring 68 opening-wide the orifice 61, as shown in Fig. 2.

When the feed motor, isstarted up, however, and the oil enters the nozzle, pressure within the-nozzle chamber 51 forces the dia phra'gm back .(seeidetted' line position in Figi'2),"withdrawing' the reduced end of the" clearingrodfi'om the orifice to a point where itdflers" Iio inter ference with the free passage of the" oi'ltherethrough andbring- 'i'ng'the high" art ofthe cam plate to bear onthe valve. stem 63' whichthereupon moves to the" position shown in Fig. {1 leaving a supplyor'1fi'c'e' having the restricted area mentioned.

lYIe'aI'is are provided for availing of the differential pressure relation between the chambers 51 and 59 (due to the restricted orifice 61) automatically to more the clearing device forward to clear the passage and thereafter tejretract it when the nozzle orifice 43 is cleared; Forihis purpose the switch 41" arranged to be opened by a pressure re aonsive device connected to the nozzle chain er. In case the orifice 13 becomes obstruc ted during the operation of the burner the pressure in the nozzle chamber 51 will immediately build up, and if the orifice 43 becomes completely closed the pressure in'th'e chambers 51 and 59 will become equalized or' approximately so. The pressure in the nozzle chamber 51 during the unobstructed flow of oil in the operathe pressure responsive; device",-;but,, with the equalization ofpressur'e inthe chambers 51 and 59 following the occurrence of an obt n, t i cr se. P R T $U Q.. n. the. chamber 51 is availed of to open the motor control switch, thereby causing stoppage of the motor and cessation of the fuel supply. This is followed; by the forward or clearing movement of the plunger under the compression' spring 66;t-he end 47 of the clearing rod thereupon serving to remove the obstruetioii and clear the orifice. Forward movement of the clearing rod is further utilized to close the'swit'ch by ame chanical con'n'ectioii between the clearing member and the switch? For this purposethe nozzlechamber is' connected byah'a-hs offlthe nipple 69th a Bourdon pressure tube 70 carried within the casing 71, the fre e end ofthe tube having connection through the link73 than oseil lating plate 7'5"piv'oted at 77 betweenthe fiXedplatesTQ' and '81. The plate 7'5is'joi'nt ed to the link 83, the ne'er carrying at its"- upper end theroll 85 whichis drawn the spring 87 agaihsta \f-shap'ed piece 89, the latter mounted to r'ock'about the fixedp'ivot 91. The piece sais securedto the'gla'ss tube 93 carrying small amoiiht'of'mercury 951 The tube and its carrier are so mounted as to be capable 'of tipping about the pivot 91' to either one of the tfwo' extremelpositions represented infFig s. 2 ahd3, so that iii one" position (Fig. 2) thet'erminal's 97 of the motor circuit are immersedinthe mercurydescribed reniain" in the po'sitioii' indicated' in Fig. 2'. In case" pressure in" the nozzle chamber rises, however, through the"o'ccu'rrence' of an obstruction iii the orifice, the tube segment will tend, to st'rai'ght'hgrbck ing the oscillating plate'Z5 right haiidedly;

drawing down the link 83;ca'u'sirig the roll 85 to snap to the under side of the V.-shaped' piece 8i) andthrowing the glass tube to its pppo'site'ly inclined position represented in fig/.3

thereupon thrown forward as described. Preferablyelost motioii is provided between the link 73 and" the plate 5', as by means of the pin QSivo'rki'ng in the slot 101, sothat the switch cannot be again thrown to its closed position by the drop in pressure, a mechanical attachment betweenthe clearing member and the switch beiii'g herein relied tion of the burner is insufficient to actuate upon'for' that purpose.

This opens'the motor circuit, stops the feeding'o'f oil, and the clearing member is To again close the switch and return the parts from the position indicated in Fig. 3 to that indicated in Fig. 2 the oscillating plate is provided with apin 103 adapted to be engaged by the pivoted dog 105, the latter being fixed to the actuating arm- 107. To move the arm and throw the switch the back of the diaphragm 53 has fastened thereto an actuating member 109 which projects through a slot 111 in the nozzlechamber walls, the actuator being prolonged to engage the arm 107 through a pin and slot connection.

When the burner is' started into operation the actuator moves to the dotted line position indicated in Fig. 2, withdrawing the dog from the pin 103. lVhen the pressure responsive device operates, however, and the clearing member reaches its forward position, the actuator 109, which has been car ried forwardly therewith, turns the dog right-handedly causing it to engage the pin 103 and throw the switch to the closed position (Fig. 2). The parts are so arranged therefore that in case of obstruction in the orifice a rise in pressure of the nozzle opens the switch and the switch is not again closed until the clearing member is movedlnsures the forwardly to a position where it clearing of the orifice.

The provision of the valve-62 which opens up the normally restricted: supply orifice 61 when the clearing device moved forward serves also automatically to clear the orifice 61 of any dirt, dust or foreign matter accumulated therein and likely to interfere with the proper functioning of the apparatus. lVhile the burner is in normal operation the passage 61 is restricted in size, and any particles of foreign matter lodging therein and likely to materially reduce its cross sectional area below a suitable point will be promptly washed out or cleared as soon as the *alve lifts on the forward movement of the plunger 45.

lVhile I have herein shown and described for the purposes of illustration one Specific embodiment of the invention and one particular application thereof, it is to be understood that the same may be usefully applied to other purposes and that extensive deviations and changes may be made in the details and the form and relative arrangement of parts, all without departing from the spirit of the invention.

Having described my invention, What I claim as new and desire to secure by Letters Patent is:

1. In an apparatus for burning liquid fuel, the con'ibination with a nozzle having an orifice, of a movable clearing device for said orifice, supply passages through which liquid fuel is fed under pressure to the nozzle, said passages being proportioned to provide for substantial increase in pressure in the nozzle BEST AVAILABLE COP on an occurrence of-an obstruction in said I orifice, a fuel pump, a feed motor, means for causing the retraction of the clearing device under pressure of the fuel fed to the nozzle, means for forcing the clearing device to a clearingposition when the nozzle pressure drops, a motor switch, pressure responsive device responsive to pressure increase at the nozzle for opening said switch, and means responsive to clearing movement of the clearing device for again closing said switch.

2. In a liquid fuel burning apparatus, the combination with a nozzle having an orifice, of a movable clearing member with means tending to move the same to clear the orifice, means responsive to pressure of the fuel in the nozzle for retraction of the member, a fuel supply pump, a motor, a switch with means for moving the same to open the motor circuit following the occurrence of an obstruction in said orifice, and means for again closing said switch following the clearing movement of said member.

3. Anapparatus'for'burning liquid fuel comprising a nozzle having a discharge orifice, means for supplying fuel under pressure to the-nozzle, a clearing device comprising a plungerhaving an end adapted to enter and clear theorifice, and plunger moving means normally forcing said plunger to a clearing position but responsiveto' the pressure of liquid fuel to retract the clearing device from the orifice, said plunger moving means being automatically controlled in response to an obstruction in the orifice during the operation of the burner first to move said plunger to. its clearing position and then to retract the same therefrom.

4. In an apparatus for burning liquid fuel, the combination with a nozzle having a discharge orifice, of a clearing device for the orifice retracted under the pressure of the fuel in the normal operation of the burner, devices responsive to the occurrence of an obstruction in the orifice for stopping the fuel supply and causing a clearing movement of the clearing member, and means for restoring the fuel supply and retracting said member following its clearing movement.

5. In an apparatus for burning liquid fuel, the combination with a nozzle having an orifice, of a movable clearing device for said orifice, a supply passage through which liquid fuel is fed under pressure to the nozzle, said passage being proportioned to provide for a substantial increase in pressure of the nozzle on an occurrence of an obstruction in said orifice, means responsive to pressure increase therein for moving the clearing member, and means automatically also to clear said passage, said means comprising a valve serving to restrict said passage in the normal operation of the burner and means to open said valve on the clearing movement of the clearing device.

6. An apparatus for burning liquid fuel comprising a nozzle having an orifice and a movable clearing member, power-driven, pressure-creating means for feeding fuel unfiz der pressure to the nozzle, means for movom the or fi e-- ing the clearing member including a diaphragm subject to the pressure of the fuel being fed and serving normally to withdraw the clearing member from the orifice during the operation of the burner, and a device responsive tothe rise in pressure of the fuel in the nozzle on the occurrence of an obstruction in the orifice, said device serving to control the pressure creating means to reduce the pressure acting against Said diaphragm nd to Cause h l t r t p oj ct the e ri g member through the orifice, but subsequently toiincrease said pressure to cause the dia- Phliflgm .to ithdraw the clearing member ,7, pparatus for burning liquid fuel c mprisinga nozzlehaving an orifice and a movable clearing member withdrawn from the orifice during the normal operation of the burner, pressure creating means compris- QEST AVAlLABLE cOP trol said pump and reduce the pressure at the nozzle, thereby to cause the "moving means to move the clearing member to an orifice clearing position, and pump controlling devices falso connected to the clearing member and adapted ,to be set in operation by theclearing movement thereof to restore working pressure conditions atthe nozzle and to-cause the clearing member to withdraw f'rom the orifice.

8. An apparatus for burning liquid fuel comprising a nozzle having an orifice and a movable clearing member Withdrawn from the orifice during the normal operation of the burner, means comprising a powerdriven pump for feeding fuel under pressure to the nozzle, means including a pressure responsive device, responsive to an increase in orking pressure at the nozzle following the occurrence of an obstruction in the orifice, toact on said fuel feeding means and change the pressure at said nozzle, thereby to cause the clearing member to move to an orifice-clearing position, and devices, connected 1 the clearing member to be set in operation by the clearing movement thereof and acting on said fuel feeding means to restore orking pressure conditions at the nozzle and cause the clearing member to withdraw from the orifice.

In testimony whereof, I have signed my name to this specification.

ARTHUR H. BALLARD. 

